System of control.



R. E. HELLMUND.

SYSTEM OF CONTROL. APPLICATION HLED MAYH. l9l6.

1,231,604. Patented July 3, 1917.

Ground INVENTOR WITN SES:

Qudolf E. Hel Zmunol. BY

county of Allegheny and State 0 UNITED STATES PATENT OFFICE. BUDOLF E.HELLMUND, OF-IPITTSB'URGI I, PENNSYLVANIA, ASSIGNOB TO WESTING- HOUSEELECTRIC AJSlD MAN'QFAGTUBING COMPANY, A COBPOBA'lPION 0F PENNSYL- VAN1A ToaZl-whom'itma concern: 7 Beit known t at I, Runonr E.

Mtmmfa subject of the Emperor of ,Ger many, and a resident of"Pittsburfgh, 1n the Pennsyl- Vania, have invented-a new and usefglprovement in-Systems of Control, of which the following is aspecification.

M invention relates to systems of control for ynamo-electric machinesand especially minedconditions.

, period, the motor-generatorset being r0 vided with an arran ingswhereby the CXCltlttOIl of the driving One object of my invention isprovide 'a stem of the above-indicated character which shall berelatively simple andiinex auxilia SYSTEM Q1! CONTROL.

Patented July 3, 191 '7.

armature winding G a field winding GF for the armature G that'isconnected in series relation with the driving armature M, and a fieldwindin MFl for the armature M that is mdepen ently excited by a suitableauxiliary source of energy, such as a storageb'attery B. I The armaturewindings M and G of the motor-generator set may be mechanica y connectedin any suitable man toithe regenerative control of electric railwaymotors and the 1ike,-under predeter I mgare respectit' pensive inconstruction and efl'ectivej andf reliable in operation and which;-.shal l"embody novel means, comprising an auxiliary source of energy, torexcitingthe driving motor of a motor-generator .set"tli at is arepreferably composed of laminated magemployed for main-field-windingexcitation purposes, under regenerative conditions, whereby flash-overtroubles in the drivotor are eiiectively revented. j

invention to provide an auxiliary motorcircuit and adaptedtoiexcite thema-. chine field windings during the regenerative motor thereof isautoma lcall'y increased to a 'redetermined value upon an interruption ovoltage to the drivin motor, as herein: after more fully set for sectively having armatures A1 and A2 and.

eld-magnet windings F1 and F2 of the series type; a plurality ofmain-circuit resistors R1 and R2 that are associated with the mainarmatures in a manner to be described; a motor-generatorset comprisinggenerator set tobe driven from thesiipply ner, as by a shaft 8, and themotor armature winding and the enerator armature windy adapted to bedriven from the suppl circuit and to'excite the .main field windings F1and F2, as set forth in detail later. The series field winding GF forthe armature} winding G' is disposed upon a pluralit ofpolarprojections, here represented by t e-single rectangle P, whichnetizable material in order toproduce a relativelyhighly j inductiveeffect, for a pur-,

pose tofbe described. An auxiliary resistor A R2 islada ted tobe'connected in shunt relation'to t 'e field winding GF upon the closureof a switch 4, and the resistor may be varied in active circuit value bysuitably mampulatmg' a plurality of switches 5 and 6, whereby theeffective exciting action of ent of field wind- {heds'eriesfield'winding GF may be reguate a The. field winding :MElof thedrivingiarmature M' 'isc'onneoted in series" relation witha variableresistor ARI across the batte'ry B, and the resistor may be regulatedmeans through theagency of a plurality My invention may best be byreference, to the accompanying drawing, Jug v.

- nasmuch as my present invention perof silitableswitohs 2 and '3,tlru's determinin the excitation of thearmature windtains onlyindirectly to the type of .regeni a driving armature winding M, anexciting eration of the mainv machines.

and claime are as illustrated in Fig. 1, such connections may be tracedas follows: One mam circuit is established from the trolley throughjunction-point 10, conductor 11, main armature A1, j unction-point 12,maincircuit resistor R1, a switching device 13,

here. conventionally shown as an arrow-.

switching device 19, which corresponds to v fi 1 an junctiori-pomt 14,where the circuit the other witching device 13, and thence throughjrdiction-point 14, as just one terminal 20. of the exciting armature Gof the motor-generator set is connected conductprs21 and 22 to conductordivides, one branch including switching device 13, main-circuitresistor- R1, junctionpoint-12, main field-winding I doctor. 23tojunction-point 24, and the other branch including switching device-19and F1 and conmain-circuit resistor R2, junction point 18, main field F2and the Junctionpoint '24, whencecircuit is completed through conductor25 to the ,other terminal 26 of the exciting armature G.

An auxiliary circuit is complet from the conductor 16 through conductor27, the driving armature winding M of themotorgenerator set, conductors28 and 29, the series field winding GF for the armature winding G andconductors 30 and 22 to the negative conductor Ground. The auxiliaresistor AR2, 'wheii the switch 4 is close is connected betweenconductors 28 and 30, and is thus connected in direct parallel relationto the series field GF.

The operation of the above-described system may. beset forth in generalas follows:

Upon an'jncipieiit of regenerated current in the main-armature- "forexample,-a correspondingly in volta drop across-the main-circuitresistor R1 0 tains, whereby the volta available for delivery to themain fiel winding F1 from the approximately constant-voltageexcitingarmature is accordingly 'reduced'and' by reason of such negativecompounding eii the current traversing the-main armature AL isinherently and immediately identified co-pending application, but it isbelieved that the foregoing brief descripture, the converse action ofautomatically strengthening the corresponding field excitation, willtake place.

reduced to the normal value. The rtegulating action just outlined isfully set f0 in my abovef However, under the above-mentionedcircumstances of an incipient increase of regenerated current in thearmature A1, a further effect is produced, in that the decreasedexciting current that is necessarily delivered by the auxiliary armaturewinding G under such conditions, causes a corresponding reduction in theload of the motor-generator set, that is to say, in the current thattraverses the driving armature winding M and the series field winding GFfor the armature G. Consequentl in addition to the previousl describenegative compounding effect 0 the main machines,

the exciting armature winding G is rovided with a positive compoundincharacteristic and, in the assumed case, t e field flux that is producedby the series field winding GF )8 reduced to effect a correspondingdecrease in the enerated voltage of the armature winding G and thus aidin the desired automatic maintenance of substantially constant reenerated current. It will be understood t atthe two inherent regulatingactions'that have just been described occur at a relatively rapid rate,and

the actual fluctuations of regenerated current in either main armatureare maintained within desirably-narrow limits.

To maintain the desired value of the regenerated current as the speed ofthe momentum-driven machines decreases, the switching devices 13 and 19may be suitably manipulated, preferabIy automatically in accordance withregenerated current, as set forth in my above-identified co-pendingapplication, to adually vary the active c rcuit value of t e resistorsR1 and R2 and thus compensate for the speed reduction in question.Further regulation of the regenerative operation may be efi'ected'at anytime by suitable manipulation of the switches 1 to 6, inclusive, toagain accomplish an increase of the main field-winding excitation asthe. speed of the momentumdriven vehicle decreases.

:Ohe of the principal advantages of the above-described system residesin its in herent ability to prevent flash-over conabnormal conditions,such' as the sudden resumption of supply-circuit voltage after atemporary interruption thereof, caused by the vehicle "currentcollcctingdevice tempoor instance.

Upon the resumption of supply-circuit voltage, the current traversingthe driving armature M tends to rapidly increase to a ditions in thedriving armature M, under rarily leaving the supply-circuit conductor,

relatively high value by reason of the comparutively low inductance of.the armature winding, whereas, in motor-generator sets embodying asupply-circuit excitcd fieldnmgnct winding, particularly of the shunttypcfsuch as has been more or loss customary in the rior art, therelatively high inductive efi eict of the field-winding circuit hasprevented a building up of the field flux as rapidl as the simultaneousarmature current ux, whereby an. undue distortion of the fieldflux, withresultantrelatively high voltage between commutator bars-and 11abilityto flash-over troubles has occurred in many cases in the past.

In my invention, however, the utilization of the field winding MFl,which is excited from the inde endent auxiliary source B, maintains a su'stantially constant field flux for the driving armature winding M andthus, upon a resumption of supply-circuit volta e after a temporaryinterruption thereof, the armature current does not increase to such avalue that the field flux is unduly distorted, or, in other words, themaintenance of a desirably stron field excitation during theabove-mentione emergency conditions effectively precludes thepossibility of flash-over troubles in the drivin motor armature windingM. Moreover, t e abnormal increase of current in the armature winding M,in. the circumstances under con-- sideration, is checked by reason ofthe highly inductive effect of the series field winding GF which iswound upon the laminated polar projections P and is connected in seriesrelation with the driving armature winding M. The well-known choke-coilaction of the field winding GF thus prevents the traversal of an undulyhigh current through the circuit of the driving armature winding.

be'had to Fig. 2 which Reference may now islike Fig. 1 as regards themain-machine,

circuits and the connectionsof the enerator or exciting armature windingG. e novel features of the systemshown in Fig. 2 reside in the relativearrangement of the field Windingsfor the auxiliary armatures M. and G,as about to be described. The motor-generator set, in addition to theauxiliary armature' windings M and G, is provided with field windings'MF and MFI forthe armatture winding M, and "field windings GF and GFlfor the other armature winding G. The battery B is employed for'excitingthe field windings MFI and GFl tlirou h a plurality of variableresistors ARI and R3, respectively.

One auxiliary circuit is completed from the conductor 16 throughconductor 35, series field winding MF, driving armature winding M,conductor 36, series field wind ing GF of the armature winding G andconductor 22 to the negative conductor Ground. An independent auxiliarycircuit is established from one terminal of the v battery B throughconductor 37, junction-point g8,

the armature winding M, variable resistor .mature winding G, varia 1eresistor AR3 and conductor 44 to the junction-point 41, whence circuitis completed throu h conductor 42to the other terminal of t e batterX B.V

s indicated by the positive signs, the so.- ries field winding GF andshunt field winding GFl-for the armature winding G are adapted toproduce a cumulative excitingefiect in that both field windin s act toincrease the delivered voltage of the armature winding. The shunt fieldwinding MFl for the drivingjarmature M performs a'similar function, but,as indicated by the no tive sign and the legend Differential, t e se-'ries field winding MF tends to oppose the ositively energizing actionof t e shunt field winding MFl, or, in other wor the two field windingsMF and MF]. are differentially related with respect to each other,-. andthe effective flux that threads the driving armature 'M corresponds tothe differcnce of he fluxes that are produced by .the two fieldwindings.

The normal operation of the system shown in Fig. 2 is very similar tothat set forth in connection with Fig. 1, but a difi erent action takesplace under the above-mentioned emergency conditions, namely, thesudden-resumption of supply-circuit volta e after a-temporaryinterruption thereof.

nder such circumstances, the opposing action of the series field windingMF disappears, while the full ositively energizing efi'ect of the shuntfield windin MFl acts uponv the driving armature M. suitable design ofparts, therefore, the driving armature Mmay be provided with a greaterfield excitation 'during the above-mentioned im terruption of suply-circuit voltage it has under norm operating eonditionswhen opposinaction of the series field windmg MF ta es efiect. It should be notedthat, even though the interruption of supply-circuit voltage is ofsuflicient duration to permit of a certain reduction in speed of themotor-generator set, theincreased field? excitation provided-=1) thei'hd'epetideiftly' excited shunt field winding 'MFI will 'be sufiicientto prevent the previously described undesirable predominance of restoredarmature current flux over the simultaneous field winding flux, wherebyflash-over conditions will be effectively prevented.

It will be understood that regulation to offset the efiect of decreasingvehicle speed is accomplished in a manner similar to that set forth inconnection with Fig. 1, namely,

gradual exclusion from circuit of the main resistors Bland R2 by theswitching devices 13 and 19, and manipulation of the switches'l to 6,inclusive, to gradually speed excitation of the thus gradually increasethe current traversnected -to excite 'sai up the motor-generator set andincrease the armature winding G, to

ing the main fieldwindings.

I do not Wish to be restricted to the specific circuit connections orlocation and arrangement of parts herein set forth, as variousmodifications thereof may be efi'ected without departing from the spiritand scope of my invention.- I desire, therefore; that only suchlimitations shall be imposed as are indicated in the appended claims.

I claimas my invention:

1. In a systeni'of control, the combination with'ai supply circuit and amain dynamoelectric machine having an armature and a field winding, of aplurality of mechanicallyconnected armature windings respective y drivenfrom said supp] circuit and co d li eld winding, and means other thansaid supply circuit for providing excitation for one of saidarmawindings therefor, and

ture windings.

2. Ina system of control, the combination with a supply circuit and amain dynamo: electric ma ine'having an armature and a field winding, ofa plurality of mechanicallyconnected armature windings one of which isconnected to excite said main field winding, auxiliary field windingsfor said armaturewindin and means for exciting one of said auxiliaryfield windings independ ently of said supp] circuit.

3. In a system 0 control, the combination with a supply circuit and amain dynamoelectric machine having an armature and a field winding, of aplurality of mechanicallyconnected armature win ings for respectivelyexciting said field winding and driving said armature windings,auxiliary 'field means independent of said supply circuit for providinexcitation for said driving armature W111 ing fieldwinding,

r mo electric and means independent 4. In asystem of control, thecombination with a supplycircuit and a main dynamoelectric machinehaving an armatureand a of a pluralitg of mechanicallyconnected armaturewin ings I-respectively driven from said supply circuit and connected texcite said field winding, auxili field windings for said armaturewindin of said supply 011- cuit for exciting the auxiliary field windingcorresponding to the driving armature wind- 5. In a system of control,the combination with a of a' plurailty of mechanica y-connecte armaturewindings respectively driven from said supply circuit and connected toexcite said field winding, an

a field windin auxiliary s0urce of energy independent of said supplycircuit, and auxiliary field windings for said armature windingsrespecsupply circuit and a main dyna-v machine having an armature andtivel excited from supp y circuit.

6. In a system of tion with a field windin of a cally-connecte a supplycircuit and mo-electric machine having an said sour'ce and said control,the combinaa mam dynaarmature and 7. plurality of mechaniarmaturewindings respectively driven from said supply-circuit and connected toexcite said field wmding,

auxiliary source of energy, an auxlliary field winding for the drivingarmature winding energized from said source, and a relativelyhighlyinductive field winding for the excitlng armature winding connected inwinding. 7. In a series relation with the driving armature system ofcontrol, the combination with a supply circuit and a main dynamoelectricmachine a field winding, of a having an armature and plurality ofmechani- 35 sally-connected armature windings respectively driven fromsaid supply circuit and connected to excite said field winding, an

auxiliary source of field windings for said armature windings energy,and auxiliary energized from said source.

8. In a system of control, the combination with a supply circuit and amain dynamoelectric machine a field windin of a call -connecte having anarmature and plurality of mechani- '95 armature windings respective ydriven from said supply circuit and connected to excite said fieldwinding, an

auxiliary source of energy field windings for each 0% and a pair ofsaidarmature windings respectively energized from said source and saidsupply circuit.

9. In a with a supply electric machine havi field winding, of a systemof control, the combination circuit and a main dynamong an armature anda plurality of mechanically-connected armature windings respectivelydriven from said supply circuit and connected to excite auxiliary sourceof field windings for said field windin energy, and a pair of each ofsaid armature lated.

10. In a system of control, the combination with a supply circuit and amain dynamo electric mac 'ne having an armature and a field windi g, Ofa cally-connected arma tively driven from connected to excite auxiliarysource of plurality of mechaniture windings respecsaid supply circuitand said field winding, an energy, auxiliary field windings for saidarmature windings ener- 12 gized from said source,

and additional field windings connected in series relation with thedriving armature tively adapted to pro a cumulative effect winding andrespecduce a differential and with respect to the 13( source-excitedfield windings of the driving and the exciting armature.

11. In a system of control, the combination with a supply circuit and amain dynamo'electric machine having an armature and a field winding, ofa plurality of mechanically-connected armature windings respectivelydriven from said supply circuit and connected to excite said fieldwinding, and a set of field windings for the driving armature arrangedto automatically produce an increased exciting flux upon an interruptionof voltage to the driving armature.

12. In a system of control, the combination with a supply circuit and amain dynamo-electric machine having an armature and a field winding, ofa plurality ofmechanically-connected armature windings respectivelydriven from said supply circuit and connected to excite said fieldWinding, an

auxiliary source of energy, and a pair of difierentially-related fieldwindings for the driving armature respectively energized from saidsource and said supply circuit in such manner that an increased excitinthreads the driving armature upon an mtcrruption of voltage thereto.

In testimony whereof, I have hereunto subscribed my name this 26th dayof April 1916.

RUDOLF E. HELLMUNDi

